1. Field of the Invention
The present invention relates to a base station controller for a radio communication network, and particularly, to a technique for collecting information upon occurrence of communication failure.
2. Description of the Related Art
Functions of a base station controller (or, Radio Network Controller (RNC)) in a radio communication network are classified into a C-plane (Control-Plane), a U-plane (User-Plane), and a T-plane (Transport-plane). The C-plane handles a call setup control process. The U-plane handles a user data transmission process. The T-plane handles an interface termination process.
Each plane includes a plurality of subunits having the same functions, respectively. The subunits take partial charge of the functions of the plane to which they belong. Generally, there exists a plurality of subunits having similar functions in the same plane.
Each of subunits has a controller and a plurality of process entity for executing the process to be handled by the subunit.
Japanese Patent Application Laid-Open No. 2004-032333 (Literature 1), Japanese Patent Application Laid-Open No. 2004-194064 (Literature 2), and Japanese Patent Application Laid-Open No. 2004-247823 (Literature 3) disclose such a prior art. These literatures, however, omit description about the T-plane.
A communication operator manages a base station controller in such a radio communication network. The communication operator, upon receiving a claim from a user, investigates its cause. To perform such investigation, the communication operator needs a tool for collecting only the minimum necessary information.
For example, upon receiving a claim from a user notifying that an abnormal call release occurred, the communication operator needs to identify the cause of error. In order to identify the cause of error, the communication operator has to identify the subunit in which the error occurred, and to identify the process entity which caused the error in this subunit. Further, the communication operator collects information relating to all of the processing entities which handled the abnormally released call. The communication operator tries to investigate the cause based on the collected information.
The collected information does not only include the information relating to parts which caused the error but also includes the information relating to parts which did not cause the error. Since enormous is the quantity of the information to be collected and to be analyzed, it takes long time for the communication operator to identify the part or parts which brought the error of the specified call.
The base station controller processes an enormous number of calls. Therefore, due to the enormous amount of data to be collected and analyzed, investigating the cause takes a long time. Additionally, in a radio network system supporting multi-call, the amount of data per user increases.